A zero insertion force (ZIF) socket is a chip socket into which it is possible to couple a pin grid array (PGA) chip without any downward insert force. A conventional ZIF socket includes a base, a slidably moving cover or sliding plate attached to the base, and a lever. The PGA chip is attached to the cover, and the lever is used to slide the cover relative to the base in order to make electrical contact between the PGA chip leads and corresponding contacts in the ZIF socket base.
ZIF sockets are used where chips may be regularly moved in and out of a socket. The ZIF socket is desirable over conventional chip sockets because the use of a high density lead arrangement on the PGA chip and the corresponding receptacles on a socket calls for the use of a large insertion force in the conventional chip sockets. This large insertion force may damage the PGA chip leads during insertion or removal.
While ZIF sockets having actuation mechanisms, such as levers, are well suited and acceptable for many uses in the industry, the levers can take an unacceptably large amount of space on the printed circuit board. Furthermore, the sockets must be spaced apart to permit operation of the levers. Accordingly, there has been considerable time and effort placed in reducing the size of ZIF sockets and eliminating the levers from the ZIF socket structure.
FIG. 1 shows a perspective view of a prior art "lever-less" ZIF socket 20 for connecting a PGA chip 22 to circuits on a printed circuit board 24 on which ZIF socket 20 is mounted. A lead surface 26 of PGA chip 22 includes a plurality of leads 28. Leads 28 are inserted in corresponding receptacles 30 of ZIF socket 20. A cover portion (not shown) of ZIF socket 20 may cover receptacles 30 such that leads 28 are positioned through corresponding holes in the cover portion prior to insertion into receptacles 30.
FIG. 2 shows a top view of one of receptacles 30 of ZIF socket 20. Each of receptacles 30 has a generally circular base section 32 and a neck 34. Receptacles 30 are oriented in ZIF socket 20 such that necks 34 are tilted approximately forty-five degrees relative to the sides of ZIF socket 20 (see FIG. 1). Leaf springs 36 are located in neck 34 of each of receptacles 30. In operation, leads 28 are inserted into corresponding base sections 32 of receptacles 30. Force, as depicted by an arrow 38, is then applied to edges 40 (FIG. 1) of PGA chip 22 to slide PGA chip 22 across the surface of ZIF socket 20. Thus, leads 28 are disposed into necks 34 and in electrical contact with leaf springs 36 without the use of a downward insert force.
PGA chip 22 may be a microprocessor chip to be installed in a consumer computer system during system assembly. Alternatively, following system assembly the need may arise to remove and/or replace PGA chip 22. For example, it may be desirable to replace PGA chip 22 with an upgraded chip or PCA chip 22 may be malfunctioning thus necessitating replacement of PGA chip 22. Accordingly, a need exists for a tool that can effectively couple and decouple PGA chip 22 from a "lever-less" ZIF socket, like ZIF socket 20, in a manufacturing environment and in a post-manufacturing environment, such as a repair shop.